As an uplink radio access scheme of a next-generation communication system, studies are being conducted for a frequency domain equalization single carrier transmission scheme (SC-FDE: Single Carrier with Frequency Domain Equalization) using CP (Cyclic Prefix). In the frequency domain equalization single carrier transmission scheme, data symbols assigned in the time domain are transmitted with a single carrier.
A technique is disclosed in Non-Patent Document 1, as one of frequency domain equalization single carrier transmission systems. This technique will be explained below.
The transmission system disclosed in Non-Patent Document 1 generates a signal by attaching a CP, which is a copy of a predetermined portion at the tail end of a data block, to the beginning of the data block (see FIG. 1). The length of the attached CP is set to be longer than a propagation delay difference between terminals transmitting signals simultaneously at different frequencies and delayed waves occurred in a multi-path channel. This is because when there is a delayed wave exceeding the CP length, interference occurs between FFT (Fast Fourier Transform) blocks, which are FFT processing units (hereinafter “IBI (Inter Block Interference)”) and received signal quality degrades.
The single carrier signal with a CP attached as such is transmitted from a transmitting apparatus, the direct wave and a delayed wave are combined in a channel and the combined signal arrives at a receiving apparatus. The receiving apparatus performs timing synchronization processing on the received signal and extracts a 1 block length signal from the beginning of a block of the direct wave. The extracted signal includes the direct wave component, a delayed wave component and a noise component at the receiving apparatus and is combined with these components. The extracted signal is subjected to equalization processing on waveform distortion in the frequency domain (frequency domain equalization) and demodulated.    Non-Patent Document 1: Falconer, D.; Ariyavisitakul, S. L.; Benyamin-Seeyar, A.; Eidson, B, “Frequency domain equalization for single-carrier broadband wireless systems,” Communications Magazine, IEEE, Volume 40, Issue 4, pp 58 to 66, April 2002.